Various improvements have been steadily provided and accumulated for an absorbent body using a high absorbent polymer since body fluid absorbent articles such as disposable diapers, sanitary napkins and incontinence pads were marketed.
A super absorbent polymer (also called SAP or a highly absorbent resin) absorbs water and swells up to be a gel if the polymer contacts with water, has characteristics such that syneresis does not occur although some pressure is applied to the gel once water is absorbed therein and the like, and exerts a phenomenal water absorbing performance which reaches several ten times to several thousand times as much as the volume of the gel itself and the like, as it has been publicly known.
Although the simple substance of a super absorbent polymer exerts the absorbing performance as described above, the polymer can not exert the absorbing performance unless the polymer is placed in a wet state to some extent and since the water absorption rate is low, in an absorbent body, the polymer is mixed, for example, in the form of granular powder, crushed powder or pellets in absorbent fibers such as crushed pulps, rayon and the like.
Since in recent years, this kind of absorbent articles have problems such that it is inconvenient to carry them due to their volumes, storability is bad, a fitting property to a human body is bad, and the like, and a higher efficiency of distribution and resources-saving are required, thinning and densification have been promoted by performing press working on articles.
However, since for an absorbent body thinned by pressurization, the volume density of the absorbent body (crushed pulp and the like) extremely increases, the absorbing performance (absorption amount, absorption rate, transparency of solution) may deteriorate.
Therefore, although a number of basis weights are normally arranged so as not to allow the absorbing performance to drop while performing thinning and densification on an absorbent body, an extreme thinning cannot be promoted in this case. If the density of the high absorbent polymer becomes excessively high by thinning, there occurs so-called “gel blocking” that voids between swollen absorbent polymer particles become extremely small, thus a desired absorbing performance cannot be expressed. As a result, observed is a phenomenon that bonding between absorbent polymer particles inhibits the permeation of urine and the urine whose permeation is inhibited backflows and is discharged.
On the other hand, since an absorbent body thinned by pressurization is hardened by an increase in the volume density, if this absorbent body is applied to an absorbent article which is used in contact with a human body, there occurs a problem such that a user does not feel comfortable about the existence of a hard material, that wrinkles are largely formed in it, and the like, and thereby a leakage is likely to take place.
Therefore, the major object of the present invention is to provide an absorbent body capable of exerting an absorbing performance equivalent to an absorbent body in earlier technology, which is not thinned, while thinning is promoted and a method for manufacturing the same and an absorbent article.
Another object of the present invention is to provide an absorbent article capable of exerting an absorbing performance equivalent an absorbent article in earlier technology, which is not thinned, while thinning is promoted, and an absorbent article provided with a sufficient flexibility.
In addition, as shown FIG. 60, marketed is a disposable diaper where fastening tapes 3 and 3 are attached to both flaps F and F on the back side B respectively and when wearing the disposable diaper, the diaper is fastened in place at a predetermined region on the external surface of the belly side A. These fastening tapes 3 and 3 can be used when a disposable diaper is fastened in place with a carrion side rounded inwardly to dispose the disposable diaper after use.
The first prior example of this fastening tape 3 is an adhesive tape type. As shown in FIG. 61, there is one such that an adhesive portion 4 is formed on the entire inner surface of the extended portion from the side edge to the outside of a flap F, and fastening is performed directly on the external side of the belly side A or on an adhered tape 2 which is called a so-called front target tape fixed at the external side of the belly side A with the adhesion of the adhesive portion 4. A peeling tape 6 to redouble and temporarily hold the extended portion of the fastening tape 3 as a chain double-dashed line arrow shown in the figure is provided on the inner surface of the flap F. A tab tape 5 having a color which can distinguish the surroundings at the top portion of the adhesive portion 4 in the illustration example.
In the first prior example, if affixing is repeatedly performed on an adhered tape 2, the deterioration of an adhesion is observed. In addition, if the adhesive portion 4 is allowed by mistake to contact with a region other than the adhered tape 2, namely, a non-woven fabric surface, the adhesion deteriorates as the fibers of the non-woven fabric are attached to the adhesive portion, and it can be no longer used for fastening thereafter.
On the other hand, in a disposable diaper used recently, marketed is a disposable diaper where fastening is performed by a mechanical engagement with a surface fastener tape comprising a hook portion and a hook receptacle portion in place of an adhesive type-fastening tape, and thereby the above-mentioned problem is solved. Particularly, in a disposable diaper for adult, this tendency is strong from the viewpoint of facts that a high fastening strength is required and the like. As shown in FIG. 62, as the concrete example of the surface fastener type as the second prior example, there is one such that a hook portion 7 is provided on the inner side of the portion extended from the edge side to the outside of a flap F, a peeling tape 8 having a hook receptacle portion on the inner side of the flap F is provided and a hook portion 7 with a product unused is temporarily fixed at the peeling tape 8 in place. In addition, there is another one such that no peeling tape 8 is provided and a hook portion 7 is allowed to be tangled with the inner non-woven fabric of the flap portion F and is temporarily fixed in place.
However, since in the first prior example, a peeling tape is indispensable as described above, there is a problem such that a cost was increased by a portion of the arrangement of the peeling tape.
On the contrary to this, in the second prior example, the surface fastener-type fastening tape is excellent in repeatable detachability.
Therefore, since in each prior example, a non-air permeable adhered tape is provided on the surface of the fastening region on a belly side, it has problems such that this inhibits the air permeability on the belly side and the appearance is not neat.
In addition, although the inventors have considered an engagement where a direct entanglement with a back sheet is performed without using an adhered tape, the inventors have encountered a problem such that there is no mark of a region to which an engagement portion is to be fastened.
Accordingly, another object according to the present invention is to form a marked portion (target) on the external surface of a region to which the engagement portion is to be fastened although an adhered tape is not used. Moreover, another object is to provide a form where the appearance may not deteriorate although a distortion processed portion is formed in a large area. Furthermore, another object is to enable a user to engage and fix a fastening tape at a free position without paying a care to the engagement position of the fastening tape as a result. Moreover, another object is to provide a form where a cottony state can be prevented although the repeatable engagement and fixation of a fastening tape is performed when the external surface of a belly side is formed with a non-woven fabric. Further, other objects may be estimated from the descriptions below.